1. Field of the Invention
The present invention relates to an array substrate and a display device having the array substrate. More particularly, the present invention relates to an array substrate which controls vertically aligned liquid crystal molecules using an electrode having a slit pattern formed thereon, and a display device having the array substrate.
2. Description of the Related Art
A liquid crystal display (“LCD”) device is a type of flat panel display (“FPD”) device which is widely used. The LCD device typically includes a first display substrate, a second display substrate disposed opposite to, e.g., facing, the first display substrate and a liquid crystal layer interposed therebetween. When an electric field is applied to the liquid crystal layer, an arrangement of liquid crystal molecules in the liquid crystal layer is altered. As a result, an optical transmissivity of light through the liquid crystal layer is controlled, and an image is thereby displayed on the LCD device.
The first display substrate and the second display substrate of the LCD device typically include respective electric field-generating electrodes disposed thereon. Specifically, pixel electrodes are arranged on the first display substrate in a substantially matrix pattern, and a common electrode is formed on an entire surface of the second display substrate. In the LCD device, the image is displayed by applying a separate voltage to each pixel electrode. As a result, a thin-film transistor (“TFT”) for switching the separate voltage applied to each of the pixel electrodes is connected to each of the pixel electrodes. More specifically, a gate line which transmits a signal for controlling a switching operation of the TFT is formed on the first substrate, and a data line which transmits a voltage to each of the pixel electrodes is formed on the first substrate.
A viewing angle of the LCD device is generally lower than, e.g., narrower than, viewing angles of other types of display devices. In attempts to increase, e.g., improve, the viewing angle of the LCD device, various technologies have been developed. For example, liquid crystal molecules may be vertically aligned with respect to a plane defined by the first display substrate and the second display substrate, and a slit pattern or a protrusion pattern is formed on the pixel electrode and/or the common electrode, thereby dividing the pixel into a multi-domain structure having multiple viewing angles.
To increase the number of domains in a unit pixel of the multi-domain structure, the pixel electrode may be further divided into sub-pixel electrodes. In operation utilizing a charge-sharing driving method, for example, pixel voltages having different levels are applied to the sub-pixel electrodes.
However, in the multi-domain structure, and particularly in multi-domain structures including four or more domains per unit pixel when the sub-pixel electrodes are formed in one unit pixel, required numbers of switching elements, data lines and gate lines are increased, thereby substantially decreasing an aperture ratio of the unit pixel, resulting in a substantial degradation of an image quality of the LCD device.